batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state ============================================ WARNING: possible recursive locking detected 5.9.0-rc4-syzkaller #0 Not tainted -------------------------------------------- kworker/u4:6/23980 is trying to acquire lock: ffff888044790280 (&vlan_netdev_addr_lock_key/1){+...}-{2:2}, at: netif_addr_lock_nested include/linux/netdevice.h:4266 [inline] ffff888044790280 (&vlan_netdev_addr_lock_key/1){+...}-{2:2}, at: dev_mc_sync+0xad/0x190 net/core/dev_addr_lists.c:870 but task is already holding lock: ffff88804bc8a280 (&vlan_netdev_addr_lock_key/1){+...}-{2:2}, at: netif_addr_lock_nested include/linux/netdevice.h:4266 [inline] ffff88804bc8a280 (&vlan_netdev_addr_lock_key/1){+...}-{2:2}, at: dev_mc_unsync+0xca/0x1b0 net/core/dev_addr_lists.c:925 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&vlan_netdev_addr_lock_key/1); lock(&vlan_netdev_addr_lock_key/1); *** DEADLOCK *** May be due to missing lock nesting notation 6 locks held by kworker/u4:6/23980: #0: ffff8880a9bbc938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x6f4/0xfc0 kernel/workqueue.c:2242 #1: ffffc90012f87d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x733/0xfc0 kernel/workqueue.c:2244 #2: ffffffff897d3ff0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xac/0xba0 net/core/net_namespace.c:565 #3: ffffffff897d5d68 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock_unregistering net/core/dev.c:10865 [inline] #3: ffffffff897d5d68 (rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0x124/0x6b0 net/core/dev.c:10903 #4: ffff888093cf8280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:359 [inline] #4: ffff888093cf8280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: netif_addr_lock_bh include/linux/netdevice.h:4271 [inline] #4: ffff888093cf8280 (&vlan_netdev_addr_lock_key){+...}-{2:2}, at: dev_mc_unsync+0x8d/0x1b0 net/core/dev_addr_lists.c:924 #5: ffff88804bc8a280 (&vlan_netdev_addr_lock_key/1){+...}-{2:2}, at: netif_addr_lock_nested include/linux/netdevice.h:4266 [inline] #5: ffff88804bc8a280 (&vlan_netdev_addr_lock_key/1){+...}-{2:2}, at: dev_mc_unsync+0xca/0x1b0 net/core/dev_addr_lists.c:925 stack backtrace: CPU: 0 PID: 23980 Comm: kworker/u4:6 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118 print_deadlock_bug kernel/locking/lockdep.c:2391 [inline] check_deadlock kernel/locking/lockdep.c:2432 [inline] validate_chain+0x69a4/0x88a0 kernel/locking/lockdep.c:3202 __lock_acquire+0x110b/0x2ae0 kernel/locking/lockdep.c:4426 lock_acquire+0x140/0x6f0 kernel/locking/lockdep.c:5006 _raw_spin_lock_nested+0x2d/0x40 kernel/locking/spinlock.c:361 netif_addr_lock_nested include/linux/netdevice.h:4266 [inline] dev_mc_sync+0xad/0x190 net/core/dev_addr_lists.c:870 vlan_dev_set_rx_mode+0x47/0x70 net/8021q/vlan_dev.c:487 dev_mc_unsync+0x105/0x1b0 net/core/dev_addr_lists.c:927 vlan_dev_stop+0x47/0x320 net/8021q/vlan_dev.c:315 __dev_close_many+0x2b2/0x390 net/core/dev.c:1605 dev_close_many+0x1c1/0x4d0 net/core/dev.c:1630 rollback_registered_many+0x454/0x1380 net/core/dev.c:9261 unregister_netdevice_many net/core/dev.c:10429 [inline] default_device_exit_batch+0x42f/0x6b0 net/core/dev.c:10912 ops_exit_list net/core/net_namespace.c:189 [inline] cleanup_net+0x79c/0xba0 net/core/net_namespace.c:603 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): Released all slaves tipc: TX() has been purged, node left! device hsr_slave_0 left promiscuous mode device hsr_slave_1 left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 device bridge_slave_1 left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state device bridge_slave_0 left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state device veth1_macvtap left promiscuous mode device veth0_macvtap left promiscuous mode device veth1_vlan left promiscuous mode device veth0_vlan left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): Released all slaves